Ring Expansion of Carbocycles via Heteroatom‐Enabled Skeletal Editing

Abstract

Carbocycles serve as fundamental scaffolds in a wide range of biologically active molecules and functional materials. Traditional synthetic transformations predominantly target peripheral functional groups, while the emerging paradigm of skeletal editing enables direct remodeling of molecular carbon backbones. Among these strategies, heteroatom insertion has become a powerful approach to access high‐value heterocycles. In this review, we summarize recent progress (2020–2025) in ring expansion of carbocycles via nitrogen‐ and oxygen‐atom‐enabled skeletal editing, with an emphasis on the mechanistic paradigms of diverse strategies including transition‐metal catalysis, photochemical/electrochemical activation, radical relay cascades, and cation‐driven rearrangements. These methods enable selective incorporation of N or O atoms into inert C─C bonds, providing efficient access to diverse N ‐ and O ‐heterocycles. We also discuss the current challenges in this field, such as the development of general catalytic systems, expansion of unactivated substrate scope, and the lack of efficient insertion strategies for other heteroatoms, and provide an outlook on future development to offer insights for programmable skeletal editing and functional molecule design.